Computer pointing devices, such as mice, are among the most popular devices for interfacing with a digital computer. This is especially true in a graphic user interface (GUI) environment. Generally, in a GUI environment the position of the cursor on the computer screen (which defines the user's point of interface with a particular software package) is directly controlled by the user by moving the mouse in two dimensions on a flat surface. Movements of the mouse correspond to the two-dimensional motion of the cursor on the screen. One problem with the use of a mouse in a GUI interface is the relative difficulty of selecting a specific screen object easily and quickly. In the past, several approaches have been tried to solve this problem. For example, U.S. Pat. No. 5,298,890 of Kanamarv. et al. teaches the technique of evaluating the direction of motion of the cursor by looking at two successive positions separated by a short time interval. From this information a direction vector is established and the cursor is automatically placed at the next possible target along that linear direction. Several problems exist with this method primarily because more than one button may exist along a given linear direction, giving the resulting cursor movement a "jumpy" feel. In addition, a user may not always desire to or actually go in a straight line direction to reach the intended target.
U.S. Pat. No. 5,508,717 of Miller discloses another approach wherein different speed factors are used for certain predetermined screen locations, so that for a given mouse speed the cursor moves more quickly when remote from certain screen objects and moves more slowly in areas near the screen objects. This, however, causes the user to experience inconsistent cursor speeds even when merely crossing a button with no intention of engaging it. This not only wastes the user's time but can be very frustrating, especially in screen areas crowded with numerous potential targets.
Accordingly, a need still exists for an input device and a method of cursor control which allows a user to engage the intended screen target quickly, easily, and smoothly, without having to temporarily engage and subsequently release unwanted targets. It is to the provision of such a device and method that the present invention is primarily directed.